Why Can Bimetallic Terminals Carry Alternating Current For Extended Periods?

In modern power distribution systems, cable lug bimetal is widely used in various electrical connection scenarios. Its ability to maintain long-term stable conductivity under AC conditions is closely related to material selection and structural design. bimetallic lugs combines the physical properties of different metals, ensuring contact reliability even under high-frequency temperature fluctuations, thus achieving continuous AC current carrying capacity.

Metal Combination and Thermal Expansion Matching

bi metal cable lug uses combinations of metals such as copper and nickel, and copper and aluminum. The matching of the expansion coefficients between the metals is a crucial factor in its long-term AC current carrying capacity.

• Copper and Nickel Contact Surface: The difference in linear expansion coefficients between copper and nickel is small under temperature changes, resulting in stable contact resistance.

• Interface Tightness: Cold pressing or welding processes during manufacturing maintain a tight contact surface, improving conductivity continuity.

• Surface Oxidation Control: Surface metal treatment reduces the oxidation rate, maintaining long-term conductivity.

This combination of materials and processes allows the heat generated by bi metal lugs connectors under AC loads to be rapidly dispersed, reducing the impact of localized heating on the terminal structure.

Current Transmission and Structural Stability

During current transmission, the conductivity and mechanical stability of the bimetallic terminal block determine its long-term ability to carry alternating current. The terminal structure design considers contact area, cross-sectional shape, and clamping force to ensure uniform current flow and reduce localized heating.

Furthermore, the elastic design of the terminal contact surface allows for minor thermal expansion without loosening or gaps. Under multiple temperature cycles, the terminal contact pressure remains within the design range, and AC loads do not cause significant changes in resistance.